This study evaluated the functional results and complications of anterior cruciate ligament (ACL) surgery in adolescent females. We studied 22 consecutive female patients younger than 20 years who underwent arthroscopic ACL reconstruction. Average follow-up was 31 months. One hundred percent of the patients were satisfied. Seven patients returned to intercollegiate or high school sports. The mean Lysholm score was 94, and the International Knee Documentation Committee score was 40% normal, 60% nearly normal. KT-1000 arthrometer side-to-side differences were <or=3 mm in 90% of patients and between 3 and 5 mm in 10%. Quadriceps and hamstring strength was minimally decreased. One patient sustained a patella fracture. One patient changed her lifestyle because of her knee. Arthroscopic ACL reconstruction is successful in returning the female adolescent to competitive sports with a high degree of patient satisfaction and excellent functional outcome. Mild residual quadriceps and hamstring weakness may persist, however.